Effects of beta-adrenoceptor blocker pindolol, calcium antagonist verapamil and their combination on retention in step-down- and shuttle-box-trained rats and on brain biogenic monoamines.
The effects of the beta-adrenoceptor blocker pindolol and the calcium antagonist verapamil administered alone or in combination on retention in step-down- and shuttle-box-trained rats and on the biogenic monoamine levels in the frontal cortex and hippocampus were examined. The chronic oral treatment with pindolol impaired retention in step-down- and shuttle-box-trained rats, decreasing the dopamine (DA) and noradrenaline (NA) levels and increasing the serotonin (5-HT) levels in the cortex and hippocampus. Verapamil did not influence retention in step-down- and shuttle-box avoidance situation and the biogenic monoamine levels in the frontal cortex and hippocampus. It should, however, be noted that the chronic oral treatment with verapamil completely abolished the retention-impairing effect of pindolol, restoring to normal DA, NA and 5-HT levels. These findings might be of interest to clinical practice and suggest the necessity for using a combination of beta-blockers with Ca2+ antagonists in case of prolonged treatment of cardiovascular diseases.
Lazarova-Bakarova
M B
MB
Department of Neurotransmitter and Neuromodulator Mechanisms in the Brain, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Stancheva
S
S
Petkova
B
B
Genkova-Papasova
M
M
Alova
L
L
Boyanova
E
E
Staneva-Stoytcheva
D
D
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D015306:Biogenic Monoamines / Q000378:metabolism*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism; D004336:Drug Antagonism; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008568:Memory / Q000187:drug effects*; D009638:Norepinephrine / Q000378:metabolism; D010869:Pindolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism; D014700:Verapamil / Q000494:pharmacology
D000319:Adrenergic beta-Antagonists; D015306:Biogenic Monoamines; D002121:Calcium Channel Blockers; D012701:Serotonin; D010869:Pindolol; D014700:Verapamil; D004298:Dopamine; D009638:Norepinephrine